Does it mean anything? Can we learn anything from it? This one looks odd, what does it mean?

Looks like pretty tight quench to me

Cab quench is .040, theres about 3000 miles on these. The quench area being clean makes sense to me. What is confusing to me is that on either side of the plug it is clean, right up to the intake valve notch on each piston.

Might be fuel wash. Usually after 3000 miles the only parts that would be shiny is the qunch area. Any chance the carb was on the rich side, especially at idle or cruise?

Yes, its a DP and rich on the transition, where it ends up alot during crusing. Had been richer on cruise but I had leaned it out somewhat recently before taking this pic.

You can fix that with billet metering blocks or drilling and tapping the cast blocks. You can also drill and tap the main body for a transistion slot jet.

If the carb is rich enough to wash the piston tops then it might be washing the cylinder walls too.

Maybe it is burning all the fuel near the plug on each power stroke, todays(low carbon) fuels are not like anything we burned years ago At least all four of those cylinders look consistent

If you get a chance go to youtube and watch a few videos showing wet flow technology. The dark and light spots will make more sense. Dark areas are where the burn is cold (rich) light areas are where the mixture burns hot (lean) enough to burn the carbon away. Also fuel wash can affect the coloration of the piston and combustion chamber.

Any specific links ChevyTS? I searched but didnt really find anything

to me it looks like oil in the combustion chamber cleaning the carbon on the intake charge.

Take a look at this video. You will notice that the pattern on your pistons kind of mirrors what is happing inside the chamber. https://www.youtube.com/watch?v=DCo_7Be_o3Y

Neat stuff!

I thought that I'd read that the carboned up areas have fuel in them and the clean areas lack fuel. Maybe it is along the lines of what Chevy TS talks about with the wet flow, maybe the atomization isn't good or there isn't much swirl going on to move the fuel all around inside?

What heads are you using and can you see swirl patterns in the chamber? If it would be a fuel wash as Andy suggests, I would think you could see that in the chamber better than on the piston top.

Cylinder head: Similar pattern, a little more normal looking i.e. nothing is totally clean

It looks to me like the fuel is going tangential off the long side of the port, around the cylinder and curling in towards the center of the chamber/cylinder. It might be that the fuel gets separated out on the short side radius and mostly air is entering on that side of the intake valve blocking the rich fuel flow coming around the exhaust valve side.

Is that the Edelbrock head or the Stealth head? It may need a "wing" as Darin noted they added on their Raptor BBC head. I'd call it a bump or maybe a fin on the floor at the SSR. I've seen those on several heads over the last 10-15 years. I think Jeff K. at MCH had something like that on his SS Hemi heads. I never quite caught on that it was to aid in keeping the fuel in suspension.

That's my wild @$$ guess on what's happening. I'll be interested in what the head porters and professional engine builders have to say.

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Was the valve job on those heads redone before you used them, or is that out of the box?

PS - we can learn from everything if we have the sense to really look.

Valve job was OOTB, I lapped the valves and they produced a good pattern, but I think what youre thinking may be in line with what I'm thinking so give me your thoughts because I'm wondering if the valve job isn't up to snuff and isn't leaking.

I e-mailed some friends and one well know head porter said he thought it was too rich (already discussed) and too much timing. He thought the burn was finished before it got around to the far side away from the plug. So, something else to try.

Thanks, good to know, and I would agree that it has been too rich for sure.